3b. Thorax HAL - Worksheet

Question 1

what is the first chamber you will see passing left to right in sagittal

Answer 1

left ventricle

Question 2

what is the first chamber you will see passing right to left in sagittal

Answer 2

right atrium

Question 3

what is the last chamber you will see passing front to back in coronal

Answer 3

left atrium

Question 4

what is the first chamber you will see passing front to back in coronal

Answer 4

right ventricle

Question 5

do you encounter the atria or the ventricles first when scrolling top to bottom in axial

Answer 5

atria more so than ventricle

Question 6

what basic architectural feature helps to determine if you are looking at a ventricle or an atrium in an otherwise normal heart

Answer 6

thick muscular wall of the left ventricle

Question 7

how does the right ventricle compare to the left ventricle morphologically? How is this related to their function

Answer 7

left ventricle has more muscular walls than the right

left ventricle pumps to the rest of the body which is a higher pressure circuit so needs more muscle to pump

Right ventricle only pumps to the lungs which is lower pressure circuit and requires less power

Question 8

what important internal structures divides the atria from the ventricle

Answer 8

atria-ventricular valves (tricuspid and mitral valves)

Question 9

what is the key feature that distinguishes the thoracic vertebrae from the cervical and lumbar

Answer 9

they have ribs attached to them

Question 10

on an axial CT how can you tell if you are looking at the disks or the vertebral body

Answer 10

IV discs are less dense than bone so an compare to other bony structure to check - will appear darker than bone

bone is denser than cartilage so will be brighter white

Question 11

how many pairs of ribs are there

Answer 11

12

Question 12

why do we only see partial slices of the ribs when taken in axial cross section

Answer 12

ribs descend and then ascend again slightly and this makes it difficult to tell from a single slice

ribs are on different levels in body and don’t travel in one level, they slope down obliquely between different levels

Question 13

what 3 elements of the vertebral column do typical ribs (2-9) articulate with posteriorly to form the costovertebral joints

Answer 13

vertebral body

transverse process of own level and vertebral body of level above

Question 14

what are the 3 parts of the sternum

Answer 14

manubrium

mesosternum

xiphoid process

Question 15

what is the relation that the 3 parts of the sternum have with the chest wall as a whole

Answer 15

it slopes posteriorly from xiphoid to manubrium

Question 16

why wont you get a complete coronal view of the sternum

Answer 16

angled so wont get everything in a vertical slice

Question 17

how do you tell where the mesosternum, manubrium and sternum are in a sagittal CT chest image

Answer 17

mesosternum = beneath aorta and carina of trachea at level of heart

manubrium = anterior to great vessels

xiphi = level of liver/lower ventricles of heart

Question 18

the trans-thoracic plane sits in line with what joint

Answer 18

manubrium sternal joint

Question 19

what characteristic feature does the trachea have when compared to most of the rest of the soft tissue nearby that might help you locate it on a CT/MRI slice

Answer 19

the trachea contains air

Question 20

at what vertebral level is the trachea said to bifurcate

Answer 20

T4/5 transthoracic plane

at sternal angle

Question 21

how many lobes does the right lung have and what are their names

Answer 21

superior
middle
inferior

Question 22

how many lobes does the left lung have and what are their names

Answer 22

superior inferior

lingula

Question 23

how many fissures does the right lung have and what are their names

Answer 23

oblique and horizontal

Question 24

how many fissures does the left lung have and what are their names

Answer 24

oblique

Question 25

where is the lingual lobe of the left lung located

Answer 25

at the inferior tip of the superior lobe near the medial border

Question 26

ho far superiorly do the apex of the lungs extend normally

Answer 26

above rib 1 and behind collar bones into the lower neck region

Question 27

which relationship of the upper lobes to the lower lobes of either lung might you expect to use most on an axial chest CT or MRI slice to differentiate them

Answer 27

upper lobes are more anterior to the lower lobes lower lobes more posterior at some levels, AP association for axial slice - sup as lung fields are small and is tight, lower slice then lower lobe forms more

Question 28

what are the 3 structures entering/exiting the hilum of the lung

Answer 28

pulmonary arteries, veins and bronchi

Question 29

which of the 3 structures entering and exiting the lung at the hilum are most superiorly located

Answer 29

pulmonary arteries more superior

Question 30

what features of the 3 hilum structures help you differentiate them in practice

Answer 30

Pulmonary trunk splits into pulmonary arteries in an upside down Y shape and is the most anterior vessel of the heart Pulmonary veins are 4 in number and enter the left atrium which is the most posterior part of the heart Pulmonary trunk and arteries cross beneath the arch of the aorta

Question 31

what does the IVC enter

Answer 31

right atrium

Question 32

what does the SVC enter

Answer 32

right atrium

Question 33

what does the aorta exit

Answer 33

left ventricle

Question 34

what does the pulmonary trunk exit

Answer 34

right ventricle

Question 35

what does the pulmonary veins enter

Answer 35

left atrium

Question 36

note the ascending aorta's relative position to the pulmonary trunk in the axial slice - what might be confusing about this orientation considering where the vessels enter and exit from

Answer 36

aorta exits the left ventricle but is located on the right side of the pulmonary trunk which leaves the right ventricle this is due to the twist of the heart so the artery you see on the right in the axial view is actually the aorta leaving the left ventricle

Question 37

once the aorta has left the heart how would you describe its course how can you use this to determine if you are looking at the ascending or descending portion on the axial slice

Answer 37

it arches slightly to the left from anterior to posterior therefore anterior = ascending and posterior = descending

Question 38

in what cross sectional view might you expect to see the entire length of the aorta from ascending to descending

Answer 38

sagittal depending on how far it travels to the left from the heart

Question 39

when scrolling from superior to inferior in an axial series what order do you expect to come across the following structures imagine how they look in the axial view pulmonary arteries/pulmonary trunk/arch of aorta/ascending aorta/pulmonary veins/IVC

Answer 39

``` 1/ arch of aorta 2/ pulmonary arteries 3/ ascending aorta (and descending) 4/ pulmonary veins 5/ IVC ```

Question 40

in the axial view what is the appearance of the aortic arch

Answer 40

appears as straight length of tube

Question 41

in the axial view what is the appearance of the pulmonary trunk

Answer 41

appear as Y shape coming off pulmonary trunk

Question 42

in the axial view what is the appearance of the ascending aorta

Answer 42

appear as circular cross sections

Question 43

in the axial view what is the appearance of the pulmonary veins

Answer 43

1-2 each side entering the left atrium at back of the heart

Question 44

in the axial view what is the appearance of the IVC

Answer 44

appears as a ellipsoid structure beneath right atrium at the bottom of the heart

Question 45

the inferior aspect of the arch of the aorta and pulmonary trunk bifurcation lie on what plane at what vertebral level

Answer 45

trans-thoracic plane T4/5 vertebral level

Question 46

how might you expect the airways to appear at or around the trans-thoracic plane on an axial slice

Answer 46

variable but should start widening left-right as the trachea bifurcates or appear as 2 separate structures if slightly below the carina (left and right main bronchus)

Question 47

where are the airways in relation to most of the great vessels

Answer 47

posterior to them

Question 48

which is usually the most anterior vessel emerging from the heart

Answer 48

pulmonary trunk